Marion County Department of Public Works (MCPW)Japanese Knotweed Treatment Project, Phase II01/03
1. What is the present situation? Describe current conditions at the project sites.
JAPANESE KNOTWEED
In 2001, Marion County had thirty known sites of the state-listed noxious weed called Japanese knotweed (Polygonum cuspidatum) in its roadside right-of-ways. Through a grant in 2002 with the State Weed Board and ODA, the County was able to find an additional forty-six knotweed sites, bringing the known total to seventy-six sites.
These sites are primarily found in agricultural, forested, and rural residential areas. In some cases, the populations are spreading onto private or federal land from the roadsides. Many of these Japanese knotweed infestations are near waterways or wetlands, threatening important salmonid habitat. The forty-four populations in the county right of way were treated during the previous OSWB grant (Phase I) but require on-going treatment to ensure their elimination.
Already this weed has severely damaged riparian areas in other part of Oregon. Given the very aggressive and persistent nature of this state-listed noxious weed, the county is actively working to control the existing populations and is interested in working with both public and private landowners to eliminate the limited populations before they spread. Finding double the known total of knotweed sites during Phase I of this project suggests that Japanese knotweed is spreading in Marion County and must be addressed immediately.
We will continue to direct treatment activities toward the knotweed populations in Marion County and since it is an ideal candidate for immediate control measures. These control measures will help prevent it from becoming too widespread to contain. It is a “B” designated weed on the Oregon Department of Agriculture Weed Rating System and therefore recommended for intensive control at the state or county level.
Japanese knotweed was introduced as an ornamental plant in the United States and planted along highways for erosion control. It has the capability to rapidly invade roadside right of way, wetlands, stream banks and agricultural land, effectively out-competing the native plant populations and agricultural crops. It thrives in sun or shade, wet or arid conditions, lowland and upland, fresh and saltwater and on nearly all types of soils. It can grow under and through the roadways themselves, causing significant damage and expensive repairs. Therefore, it poses a threat to waterways, wetlands, fish habitat, native plant habitat and associated wildlife, agricultural land and our roadway system. The financial impact to the county and its citizens could be very significant if it is allowed to spread.
Seed viability of Japanese knotweed is low, and the main method of growth and spread is through its rhizomes, much like bamboo. Even one inch sections of its rhizomes are sufficient to establish new plants, whether buried three feet, under 2 inches of asphalt or floating on water, in as little as one week. This fact underscores the critical aspect of using appropriate control and removal measures to avoid unintentionally spreading this plant to new areas as existing stands are removed.
2. What are you proposing to do? Supply sufficient detail to match the project’s complexity and technical difficulty so that its viability can be evaluated.
PurposeThis Phase II grant would continue the surveys, treatments, and monitoring started in Phase I. Marion County will use those treatment methods that previously proved most effective, but also continue to explore the information available on innovative control techniques and test the most promising. Phase II will also continue the education and outreach efforts of Phase I.
Phase I accomplishments (previous OSWB grant)
1. Surveyed a majority of the county road system for knotweed populations.
2. Found 36 Japanese knotweed populations not previously identified.
3. Treated all 44 populations in the county right-of-way and supplied information for the treatment of the remaining 32 sites.
4. Worked closely with partner agencies to develop educational materials.
5. Directly contacted over 200 citizens with information about knotweed.
6. Grant partners printed knotweed fact sheets and distributed them around the area.
7. Citizens and landowners saw knotweed information at the Pudding River watershed fair and at a prominent display in downtown Salem.
8. County and city vegetation crews were trained in knotweed identification and collaborated on eradication projects.
9. The Association of Oregon Counties developed an information management system for tracking and reporting noxious weed information. This system will be available to all Oregon counties.
10. Marion County mapped and monitored all of its known sites for follow-up treatments.
11. Marion County developed an initial volunteer base to survey roadsides for noxious weed populations. This effort included school groups, adopt-a-road participants, and interested citizens.
Phase II: Proposed activities
The MCPW botanist and vegetation management foreman will coordinate all of the following activities:
1. Surveying and monitoring
2. Field treatments
3. Education and outreach
- Survey roads not covered in Phase I.
This will be done in collaboration with volunteers and MCPW field crews (who received knotweed identification training in Phase I).
- Re-survey areas near concentrations of knotweed populations.
Project coordinators will conduct road surveys in those areas with known knotweed populations, to ensure that those populations are not spreading
- Monitor previously identified sites for growth rates and response to treatments.
These sites will be monitored before and after treatments to determine the effectiveness of a given treatment.
All the information gathered from monitoring will be available to Oregon State University, Oregon Department of Agriculture, Oregon Department of Transportation, other counties, watershed councils and interested parties for use in their own monitoring, management or reporting activities. We have already transferred data to the Weed Mapper program at OSU during Phase I, and anticipate doing that with Phase II data as well.
MCPW uses a vegetation management system developed during Phase I that integrates GPS, GIS, and management databases. This system is intended to accomplish the following tasks:
q Track locations of invasive weed populations q Provide species information to Oregon State University, Oregon Department of Agriculture, and participants in the incipient weed management area group. q Allow crews to record new sites q Track monitoring data q Provide reports on species status and long-term management prescription efficacy q Provide information for field marking q Information reporting forms for crew members, external individuals and agencies
q Track locations of invasive weed populations
q Provide species information to Oregon State University, Oregon Department of Agriculture, and participants in the incipient weed management area group.
q Allow crews to record new sites
q Track monitoring data
q Provide reports on species status and long-term management prescription efficacy
q Provide information for field marking
q Information reporting forms for crew members, external individuals and agencies
We are able to create dynamic maps with periodic updates, combining overlays of threatened and endangered species locations, noxious weeds and environmentally sensitive zones. This information can be easily posted to the Internet to share with our field crews, ODOT, SWCD, WMA, the Farm Bureau and others, making it accessible to private property owners for use in their weed management efforts.
- Re-treat known populations in right of way (potentially three treatments during growing season).- Treat new populations, as they are located.
Marion County will continue to explore the most effective treatment options with agencies (The Nature Conservancy, Oregon Department of Agriculture, US Forest Service, and Bureau of Land Management) currently involved in Japanese knotweed control. This information will affect the treatment techniques. Currently, however, MCPW is proposing primarily treatment options, since this showed the best results.
Chemical treatment: Application of herbicides just before plants die back (seasonally) in September or October has been effective in control. In Phase I, the county had good success with applications of Garlon 3a/Round up. Wherever chemical control is appropriate, the county will use this treatment method.
Follow up treatments must also be made to control regrowth over a period of several years. All sites will be monitored to determine the efficacy of different treatments and the re-growth at each site. This information will be shared with other agencies facing Japanese knotweed control issues.
Manual cutting of vegetation: Stalks will be hand cut and roots dug up from sites and hauled to the Brooks waste-to-energy burner for disposal. Manual removal will be used only in areas where herbicide application is impractical.
After sufficient treatment of noxious weed sites to effectively eliminate the weed species, revegetation of these sites will be accomplished using native plants. Seeding methods will be determined by site characteristics but will likely include erosion fabric and hydroseeding in the right-of-way areas.
As our native seed inventory increases, we will have a steady supply of native seeds for revegetation of noxious weed removal sites. In addition to providing seed for Marion County projects, we will sell seed to other agencies and individuals for their restoration and revegetation projects. As private landowners participate in noxious weed removal, they will have native seed available from the county to use for revegetation of these sites. Proceeds from native seed sales will help fund county restoration projects such as Bonesteele Park and Aumsville Ponds.
- Follow-up with landowners who have knotweed populations outside of county right-of-way and encourage treatment.- Distribute knotweed information to citizens participating in watershed education events and other local activities (i.e. county fair, visits to county offices, etc.).- Continue to work with citizen volunteers through existing agreements (i.e. Adopt-A-Road participants, individual volunteers with the county, interested community groups).
Phase I educational activities:
Individuals directly contacted by Marion County:
~200 landowners, volunteers, and interested citizens
MCPW and City of Salem field crews
Numerous citizens also received information from flyers, handouts, and educational displays.
Internal training:The MCPW staff botanist conducted training with the vegetation, engineering and survey crews on two occasions. They received information about the plant, (and were shown specimens in pots) were given a list of known sites, and received a fact sheet. The groups also received a noxious weed field survey form for reporting. Additionally, the project staff put up a display in the Public Works lobby with a map showing sites found in 2001 and 2002.
External education efforts:This same information was also sent to the City of Salem vegetation management department, via Tony Day and Gene Larson. Our staff botanist personally gave it to the city road crews removing knotweed along Kuebler. The crews immediately responded by taking the knotweed from Kuebler sites to the burner instead of to the Browns Island compost pile – thus avoiding a possible massive contamination of the compost material.
Citizen education efforts:As part of the project, the Soil and Water Conservation district developed a knotweed fact sheet and widely distributed it to farmers and landowners. This same fact sheet was also used for staff education, volunteer education, and as a handout at watershed fairs.
The knotweed information package was also distributed by county staff to the Salem Audubon Society, Native Plant Society, OSU Extension office, Northwest Steelheaders, Marion County K-12 schools, City of Salem Parks and Vegetation Management crews, MC Volunteer Coordinator Glenis Chapman, educators at Chemeketa Community College and Willamette University, several boy scout and girl scout troops, and in the Vistas and Waste Matters county publications. 173 Adopt-a-Road program participants were also sent the knotweed information package. For public outreach, MCPW staff also contributed to a window display at the county offices downtown and had a knotweed information booth at the Watershed Fair at the Oregon Garden this summer.
Additionally, MCPW collaborated with Dennis Wise (WRI) and Claire Hibler (Salem BLM) and their two interns who are developing more educational materials.
Phase II will continue these efforts, but focusing primarily on private landowners.
Landowners with known populations will receive additional information on the knotweed treatment options. Additionally, MCPW will make knotweed information available at local educational events, county reception desks, and on our website. MCPW will continue to solicit volunteer help for the survey and monitoring effort.
3. What are the project’s objectives?
1. Survey and monitor roadside populations of Japanese knotweed.2. Treat all knotweed populations in the county right-of-way.3. Continue education and outreach effort to private landowners.
4. How will success be determined, i.e. what elements will be monitored/evaluated by whom, how often, and for how long?
Initial success will be determined through two primary measures: 1) Were populations of Japanese knotweed significantly reduced? and 2) Did we provide educational materials to the landowners with known populations of Japanese knotweed?
MCPW will perform the monitoring and evaluation of the Japanese knotweed sites on a seasonal basis. The knotweed populations will be monitored and treated until they are eradicated within the county right-of-way. The site evaluations will incorporate the metrics listed below as will the system evaluation.
Performance metrics:
Target treatment: 100% treatment of knotweed populations in county right-of-way.Target survey coverage: 100% of Marion County roads surveyed for Japanese knotweed.Target monitoring: 100% monitoring coverage on known sites in right-of-way.Target reduction: 50% reduction of knotweed populations in county right-of-way.
Treatment Evaluation Questions:
Of the known sites, have the number of Japanese knotweed sites been reduced and by how much?Has the average size of Japanese knotweed sites been reduced?Which treatments methods (treatment and timing) were most effective?How many sites were treated (public vs. private)?Did private landowners actively engage in the treatment of populations on their land?
Program Outreach & Education Evaluation Questions:
How many new Japanese knotweed sites were reported by MCPW crews?How many Japanese knotweed sites were reported by private individuals?How many land owners were directly contacted with noxious weed information?Where were the Japanese knotweed sites distributed?
5. Who will maintain the project and for how long?
Marion County will be responsible for maintaining the treated noxious weed sites within the county right-of-way and will work with private landowners to limit recurrence of noxious weeds on sites treated as part of this program. Since noxious weed control is a recognized priority of Marion County, MCPW will continue to perform control and assessments of noxious weed sites for the foreseeable future.
6. Which elements of the project will OSWB funds be used for?
During Phase II, Oregon State Weed Board funds will be used for field treatment, botanical surveys and monitoring.
7. How does this project fit into the statewide and/or local weed management system?
This project is designed to fit closely with existing local and regional weed management efforts. Its development is based on MCPW integrated vegetation management goals for the management and eradication of noxious weeds. This effort also fits closely with the recommendations from the Oregon Department of Agriculture’s Strategic Plan and the Willamette Restoration Initiative’s action items that prioritize the elimination of invasive species. Japanese knotweed is a state-listed noxious weed.
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Summary of Project
Phase II of the Japanese knotweed treatment project is intended to find, treat, and monitor current Japanese knotweed infestations. Marion County will approach these activities using proven methods for control and monitoring. Information gathered during these efforts will be integrated into the Integrated Vegetation Management system developed in Phase I and shared with all interested agencies. Marion County will also continue its efforts in encouraging knotweed treatment on private property.